Tufted carpet having splittable filling yarns in the primary backing



Dec. 26, 1967 H9 A, SCHWARTZ ETAL 3,359,934

TUFTED CARPET HAVING SPLlTTABLE FILLING YARNS IN THE PRIMARY BACKINGOriginal Filed March 27, 1964 vTl l. Il

f/VUU/ SECT/@NAL FALL/NG) #49040 wwprz United States Patent O 3 359,934TUFTED CARPET HAING SPLITTABLE FILLING YARNS IN THE PRIMARY BACKINGHarold A. Schwartz, Litchfield, Conn., and Morton I. Port, West End,NJ., assignors, by mesne assignments, to Patchogue-Plymouth Company, NewYork, N.Y., a

joint venture Filed May 8, 1967, Ser. No. 636,804

7 Claims. (Cl. 112-410) ABSTRACT F THE DISCLOSURE This application is acontinuation of the copending application Ser. No. 355,255, filed Mar.27, 1964, now abandoned.

This invention pertains generally to tufted fabrics formed by threadingpile yarns through a woven backing, land more particularly to improvedprimary backings which facilitate tufting operations and which provide acarrier of high tensile strength.

In manufacturing tufted fabrics such as carpets, rugs and bedspreads, awoven backing in advanced through a needle tufting machine. The pileyarns are borne by a bank of reciprocating needles which extendtransversely across the backing web and pierce the backing material. Asthe needles are withdrawn, looper members serve to hold the insertedyarns, thereby forming on the moving backing row upon row of pile loopswhich project above the backing face. In the completed fabric, thecrests of the loops remain connected or they are severed, depending onwhether a short or Ia 'long loop pile or a cut pile fabric is desired.

The quality, appearance, residual tensile strength and dimensionalstability of -tufted fabrics is in large measure controlled by thetufting characteristics of the woven backing. If the nature of thebacking is such as to induce random defiection of the tufting needles,the pile yarn stitches will be uneven and the resultant pile will havean irregular density and poor pattern definition. Thus the pile densitywill be sparse in certain areas, thereby exposing backing, particularlyin low loop constructions, and producing an effect known -as grinningHeretofore t0 compensate for this effect, additional face quired, butthis of necessity raised the cost of the fabric. Moreover; while thebacking may initially have a high tensile strength, if the nature of thebacking is such that it is subject to mutilation by the tufting needles,its tensile strength may be seriously impaired.

In an attempt to produce a backing having superior characteristics,backings have heretofore been woven of flat or ribbon-like syntheticplastic yarns, rather than of the conventional round or twisted yarns ofjute, cotton and kraftcord. Among the materials used for such syntheticflat yarn have ybeen polypropylene and polyethylene. In order to causethe tufting needles to pierce the fiat woven yarns in all instancesrather than to pierce some and to push aside others in random fashion,the ribbonlike warp and weft or filling yarns of the backing were3,359,934 Patented Dec. 26, 1967 closely woven so that the backingsurface was free of interstices.

Though such backings, when formed of fiat synthetic yarns, have certainadvantages over prior constructions, We have found that the tuftingoperation gives rise to a significant reduction in the tensile strengththereof. Our tests have indicated that the loss of strength runs as highas fifty percent of the initial tensile value in the filling.

The reason for this drawback is that the tufting needles are of oval torectangular cross-sectional shape, with the long ydirection of theneedles running parallel to the warp yarns and transversely with respectto the filling. The nature of the tufting operation is such that thebank of needles is deployed across the width of the advancing backingweb; hence at any one time the narrow cutting edge of no more than oneor two needles will strike an individual warp yarn, whereas the ywideredge of a large number of needles may concurrently strike the same weftyarn. Consequently, the weft or filling yarns are subjected to moremassive stresses than the warp yarns and ordinarily lose more tensilestrength in the course of tufting.

While the purpose heretofore of using a ribbon-like mono-filament yarnin the filling as well as in the warp is to cause the tufting needles topierce both the filling and the Warp, in practice such piercing actuallytakes place in only a few instances, and in the majority of cases thefilling yarn is either fractured or pushed aside. Because such materialsas polypropylene are subject to rupture and splintering by an impact,even if the portion of the needle striking the fiat yarn cuts onlyone-half of the yarn, this transmits a shock to the remaining section ofthe yarn, thus weakening it.

IFurthermore, we have found that in weaving a backing of flatmono-filament synthetic plastic yarns, the nature of the weavingoperation is such that in many cases there is some folding and twistingof the filling yarns, whereas there is relatively little twist impartedto the rib- !bon in the warp direction. The tufting needles, whose broadsides lie parallel to the warp, slit the fiat ribbons -with relativeease in the warp direction with a minimum of rupture and with little orno needle defiection. However, with the twisted flat yarns in thefilling, the needle action is unpredictable.

Accordingly, it is the main object of the present invention to providean improved backing for a tufted fabric which facilitates the tuftingoperation and which minimizes undesirable needle defiection effects toproduce a tufted fabric of superior quality and appearance.

Also an object of the invention is to provide a woven backing for atufted rug, whose initial tensile strength is high and Whose tensilestrength is not sharply reduced yarn was reyield by the tuftingoperation, whereby the tufted fabric is strong and dimensionally stable.

More specifically, it is an object of the invention to provide a wovenbacking -having the above noted characteristics, the backing beingformed of fiat synthetic plastic warp yarns interwoven withmulti-sectional or multi-lilament filling yarns which are readilypenetrable, whereby the impinging needles will either enter betweenadjacent filling yarns or separate closely adjacent filaments orsections of particular filling yarns and thereby pass through thefilling yarns rather than fracture or otherwise mutilate them. A backingin accordance with the invention provides improved tuft bind, since thefilling yarns are not fractured or mutilated and the pile yarns arefirmly secured to the carrier.

A significant feature of the invention resides in the fact that thetufting needles are subjected to a minimum of defiection by the warp andfilling yarns, both of which to rather than resist or oppose the needleaction, lthereby avoiding pattern distortion and maintaining the tensilestrength of the backing to a high level.

Also an object of the invention is to provide an improved backing as acarrier for a tufted fabric, which primary backing may be effectivelylaminated to a secondary backing, such secondary backing serving toimpart greater body to the tufted fabric.

Briefly stated, these objects are accomplished in a tufted fabric whoseprimary backing is composed of flat ribbon-like mono-filament warp yarnsinterwoven with filling yarns of synthetic plastic material but inmultisection form, such that a needle impinging on the filling yarn willseparate the filaments or sections thereof to pass therethrough and notbe deflected thereby. By the term multi-sectional filling yarn is meant:

(a) a yarn formed by a cluster of fine continuous filaments, preferablywith little or no twist;

(b) a yarn formed by a group of closely adjacent mono-filament yarns,preferably with little or no twist; and

(c) a yarn formed by a single mono-filament whose cross-sectional shapeis such as to produce a series of inter-connected parallel sectionswhich may easily be separated by a needle.

In the forms (a) and (b), the filaments may be held together as byadhesive or sintering.

For a better understanding of the invention as well as other objects andfurther features thereof, reference is had to the following detaileddescription to be read in conjunction with the accompanying drawing,wherein:

FIG. 1 is a sectional view of a double-backed tufted fabric including aprimary backing in accordance with the invention;

FIG. 2 is a plan view of said primary backing;

FIG. 3 shows, in perspective, the multi-filament structure of themulti-sectional filling yarn in the primary back- FIG. 4 illustrates intransverse section, a modified form of multi-sectional filling yarn;

FIG. 5 shows in section, another preferred modification of themulti-sectional filling yarn;

FIG. 6 is still another embodiment of the multisectional filling yarn;

FIG. 7 illustrates, in section, the action of a tufting needle on aprimary backing in accordance with the invention; and

FIG. 8 is a plan view of the tufted fabric, the structure being cut awayto illustrate the various layers thereof.

Referring now to FIG. 1, a tufted fabric in accordance wit-h theinvention includes a preformed primary backing constituted bylongitudinally-extending warp yarns 10 and transversely-extendingfilling yarns 11, which are interwoven on a loom in any known manner toform the carrier for the tufted fabric. Tufted into the backing is apile yarn 12 which may be of cotton, wool, or any suitable material, orsynthetic fiber, this pile yarn forming the face of the fabric.

In the loop pile machine for making tufted fabrics, each needle 13 in aserial bank thereof, as shown schematically in FIG. 8, inserts the loopof pile yarn 12 through the backing fabric (Warp 10 and filler 11) andcarries it down to a point below the hook 14. A web of backing fabric isfed continuously into the needle bank. The hooks 14 function in timedrelationship with the needles 13 and cross the needles just above theneedle eye to pick up the loop of pile yarn. The hooks then hold thisloop while the needles are being retracted from the backing, meanwhilerocking back and forth from the needle path. When the needles starttheir vnext descent, the loops have been released from the hooks and thefeed mechanism for the Ibacking has advanced the backing forward onestitch length carrying the loop away from the needle.

Thus, in FIG. 1, each loop 15 represents-one in a row of pile loopsrunning across the backing web, there being as many loops in the row asthere are needles in the bank. The distance between loops in the chainthereof running in the direction of web movement is determined by thereciprocating rate of the needle and the speed at which the backing isadvanced, this distance constituting the stitch spacing. The pile loops15 in each chain are linked by connecting loops 16 drawn against theundersurface of the carrier backing. The height of the pile may be madelow or high, as desired, or any combination of high and low loops inaccordance with known patterning practices. Alternatively, the pileloops may be cut in accordance with known techniques.

In order to porperly anchor the pile yarns and to impart the desiredbody to the tufted fabric, a relatively heavy secondary backing 17 isprovided, which is laminated to the carrier or primary `backing 10 and11 and to the underlying connecting loops 16 by means of an adhesive 18such as latex. The adhesive is applied in the fluid state and flowsfreely into the spaces between the` warp and filling ya-rns of both theprimary and secondary backings to form a film-like coating. This latexis then cured, or if other known forms of adhesives are employed, thecoating is allowed to set and harden.

The present invention is concerned mainly with the physical propertiesand structure of the primary backing and its tufting characteristics. Aspointed out previously, if the structure of the backing is such as to beruptured or mutilated by the needling operation, its tensile strengthwill be impaired and the quality of the tufted fabric will be degraded.Also, if the nature of the backing is such as to cause defiection of theneedles, so that if instead of a row of uniformly-spaced loops acrossthe backing and uniformly-spaced loop stitches in the direction ofbacking movement, these spaces are irregular, then grinning may occurand the pattern of the fabric will not be properly defined.

In accordance with the invention, the warp and filling yarns from whichthe primary backing is woven are made of synthetic plastic material,such as polypropylene, polyamides such as nylon, polyester orpolyacrylic yarns, as `well as vinyl and polyethylene yarns.

The warp threads 10 are preferably constituted by ribbon-like uniformmono-filament yarns of relatively fiat cross-section, highly oriented inthe longitudinal direction. This is usually accomplished by so drawingthe ribbon or the broad web from which the ribbon-like yarn is slit, asto irreversibly stretch the material, thereby orienting its molecularstructure and increasing its tensile strength. When a needle interposedin the path of a ribbon-like warp yarn, as shown in FIG. 8, strikes thisyarn, it will pierce the yarn without difficulty, for the broad side ofthe needle which has an oval or rectangular cross-section, lies in thewarp direction and the needle therefore effects a clean slitting actionwhich does not materially impair the tensile strength of the warp.

The filling threads, however, lie transversely with respect to the broadside of the needles, and should ribbonlike yarns be used for thispurpose, the needles, as pointed out previously, tend to rupture thefilling or to push it aside. The resistance offered by such filling alsogives rise to needle defiection. To avoid the drawbacks incidentthereto, the filling threads, in accordance with one embodiment of theinvention, are of multi-sectional construction, as shown separately inFIG. 3, where it will be seen that the yarn is composed of a cluster ofindividual fine continuous filaments with little or no twist, eachfilament being of about 6 to 50 denier.

Hence when the needle strikes the multi-sectional filling yarn, asshownl in FIG. 7, the cluster of filaments composing the filling isdivided rather than ruptured, and as there is little if any twist, lthispermits the needle to pass through the yarn. This yielding action of thefilaments in the cluster serves to preserve the tensile strength of theyarn. Since few if any filaments are broken, the others which constitutethe vast majority remain intact, and the rupture or impact is nottransmitted to the other filaments.

The utgrwfgvcn mono-filament warp yarns and the multi-sectional fillingyarns afford a relatively thin primary backing which is advantageous forit limits the amount of face yarn hidden in the backing. The backingfabric made in accordance with the invention is such as to minimizeneedle deflection, and a uniform stitching action is obtained whichproduces a pile of regular density with no distortion of the pattern.Since the primary backing is relatively light-weight, a secondarybacking is necessary to impart body to the fabric, where such body isdesirable, as in rugs.

In stead of the filling yarns taking the form of a cluster ofindependent continuous, fine filaments, one may also use a filling yarncomposed of a group of closely adjacent mono-filament yarns ofrelatively large denier in the order of 50 denier and above. Theindividual iaments in the :cluster or group thereof may be of roundcrosssection or in any other geometric fonn, such as triangular,elliptical or square. Another suitable form of multi-sectional fillingyarns, as shown in FIG. 4, is one in which a group of individualfilaments 19 lying in the same plane are weakly joined togetherlongitudinally either by heatsintering or by the use of an adhesive. Thefilaments are so interbonded that the junction lines are relativelyweak, hence when the needle strikes the yarn it tends to part along abonding line rather than to rupture.

A similar effect may be obtained by a multi-sectional yarn 20 as shownin EIG. 5, `wherein the yarn is so extruded as to have a serrated orcorrugated cross-section. In effect, therefore, the yarn is composed ofmono-lilaments which are joined together by relatively thin and weakjunction lines, thereby facilitating penetration of the needles. In lieuof a series of serrations, the filling yarn 21, as shown in FIG. 6, mayhave a single serration producing a dumbell cross-section, so that themulti-sectional yarn is effectively composed of two filaments whichseparate and yield when struck by a needle.

When the primary backing is made up entirely of fiat yarns and is of amaterial such as polypropylene, it does not provide a good laminatingsurface, for conventional adhesives `do not bond well to such smooth,non-porous synthetic plastic surfaces. However, by the use ofmultisectional filling yarn in the backing, the surface is theneffectively composed of a myriad of fine pores, interstices, orindentations which can be impregnated by the adhesive fluid and therebyafford an improved adhesive action. Thus a primary backing in accordancewith the invention is more conducive to lamination.

While there has been shown a preferred embodiment of woven backing fortufted fabrics in accordance with the invention, it will be appreciatedthat many changes and modifications may be made therein without,however, departing from the essential spirit of the invention as denedin the annexed claims. Thus in lieu of mono-filamentary flat yarns inthe warp, multi-sectional yarns of the type disclosed herein may -beused.

While there has been shown and described a preferred embodiment oflwoven backing for tufted fabrics in accordance with the invention, itwill be appreciated that many changes and modifications may be madetherein Without, however, departing from the essential spirit of theinvention as dened in the annexed claims.

What is claimed is:

1. A tufted pile fabric comprising a primary backing Woven of warp andfilling yarns and rows of pile yarn tufted into said backing to producepile loops above said backing and connecting loops therebelow, saidfilling yarns being formed of multi-sectional synthetic plastic yarnshaving a generally fiat cross-sectional shape, each filling yarn beingconstituted by a multiplicity of longitudinally extending continuousfilaments, means holding said filaments together in a cluster andpermitting said filaments to separate without rupture of said llingyarns when subjected to the action of a tufting needle, the pile yarnsbeing firmly anchored in said primary backing.

2. A tufted pile fabric, as set forth in claim 1, wherein said means bywhich said filaments in said cluster are held together are constitutedby a slight twist in said filling yarn.

3. A fabric as set forth in claim l, wherein said warp yarns are formedof uniform mono-filament synthetic plastic ribbons of fiatcross-section.

4. A fabric as set forth in claim 1, wherein said filling yarns areformed of polypropylene.

5. A fabric as set forth in claim 1, wherein said warp yarns are alsoformed of said multi-sectional synthetic plastic yarns.

6. A tufted pile fabric comprising a primary backing woven of warp andfilling yarns and rows of pile yarns tufted into said backing to producepile loops above said backing and connecting loops therebelow, saidfilling yarns being formed of multi-sectional synthetic plastic yarnshaving a generally fiat cross-sectional shape for led by longitudinallyextending parallel sections which are joined together by relatively weakjunction lines which cause the sections joined thereby to separate whensubjected to the action of a tufting needle to permit passagetherethrough, whereby rupture of said filling yarns is prevented and thepile yarns are firmly anchored therein.

7. A fabric as set forth in claim 6, lwherein said multisectionalfilling yarns are in serrated mono-filament form composed ofinterconnected parallel sections.

References Cited UNITED STATES PATENTS 3,110,905 1l/1963 Rhodes3,317,366

161-65 XR 5/1967 Dionne 161-67 XR

1. A TUFTED PILE FABRIC COMPRISING A PRIMARY BACKING TWOVEN OF WARP ANDFILLING YARNS AND ROWS OF PILE YARN TUFTED INTO SAID BACKING TO PRODUCEPILE LOOP ABOVE SAID BACKING AND CONNECTING LOOPS THEREBELOW, SAIDFILLING YARNS BEING FORMED OF MULTI-SECTIONAL SYNTHETIC PLASTIC YARNSHAVING A GENERALLY FLAT CROSS-SECTIONAL SHAPE, EACH FILLING YARN BEINGCONSTITUTED BY A MULTIPLICITY OF LONGITUDINALLY EXTENDING CONTINUOUSFILAMENTS, MEANS HOLDING SAID FILAMENTS TO-